Thermo Fisher Scientific Inc.
MX ˙ BMV ˙ US8835561023
SecurityMX:TMO / Thermo Fisher Scientific Inc.
InstitutionAssenagon Asset Management S.A.
Latest Disclosed Ownership186,436 shares
Latest Disclosed Value $ 91,638,887
Assenagon Asset Management S.A. ownership in TMO / Thermo Fisher Scientific Inc.

On April 20, 2026 - Assenagon Asset Management S.A. filed a 13F-HR form disclosing ownership of 186,436 shares of Thermo Fisher Scientific Inc. (MX:TMO) valued at $91,638,887 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 9, 2026 disclosing 10,740 shares of Thermo Fisher Scientific Inc.. This represents a change in shares of 1,635.90% during the quarter.

Assenagon Asset Management S.A. has a history of taking positions in derivatives of the underlying security (TMO) in the form of stock options. The firm currently holds call options representing 0 of underlying shares valued at $0 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

MX:TMO / Thermo Fisher Scientific Inc. Historical Put/Call Ratio
Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date
Effective
Date
Form Security Class ID Avg Price
Paid (Est)
Reported
Shares
ΔShares ΔShares
(%)
Reported
Value
(x1000)
ΔValue
(%)
Alloc
(%)
ΔAlloc ΔAlloc (%) Cost Basis
(x1000)
Unrealized
Gain/Loss
(x1000)
2026-04-20 2026-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 186,436 175,696 1,635.90 91,639 1,372.57 0.1391
2026-01-09 2025-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 10,740 -604,595 -98.25 6,223 -97.91 0.0086
2025-10-07 2025-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 615,335 573,743 1,379.46 298,450 1,669.85 0.4081
2025-07-11 2025-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 41,592 -112,137 -72.94 16,864 -77.96 0.0250
2025-04-15 2025-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 153,729 133,719 668.26 76,496 634.89 0.1276
2025-01-14 2024-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 20,010 -31,033 -60.80 10,410 -67.03 0.0168
2024-10-23 2024-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 51,043 -420,932 -89.19 31,574 -87.90 0.0581
2024-07-18 2024-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 471,975 422,341 850.91 261,002 804.78 0.5810
2024-04-24 2024-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 49,634 -55,075 -52.60 28,848 -48.10 0.0683
2024-01-17 2023-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 104,709 13,043 14.23 55,578 19.79 0.1475
2023-11-06 2023-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 91,666 53,563 140.57 46,399 133.39 0.1436
2023-07-25 2023-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 38,103 -282,365 -88.11 19,880 -89.24 0.0688
2023-04-18 2023-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 320,468 104,912 48.67 184,708 156,432.20 0.6556
2023-01-12 2022-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 215,556 73,877 52.14 119 -99.84 0.4282
2022-10-27 2022-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 141,679 91,282 181.13 71,858 162.45 0.2758
2022-07-27 2022-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 50,397 -187,183 -78.79 27,380 -80.49 0.1015
2022-04-25 2022-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 237,580 170,109 252.12 140,327 211.71 0.3899
2022-02-01 2021-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 67,471 -90,609 -57.32 45,019 -50.15 0.1304
2021-10-19 2021-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 158,080 84,077 113.61 90,316 141.93 0.2888
2021-07-15 2021-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 74,003 -36,705 -33.15 37,332 -26.11 0.1267
2021-04-26 2021-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 110,708 -10,470 -8.64 50,525 -10.48 0.2050
2021-02-01 2020-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 121,178 119,006 5,479.10 56,442 5,785.51 0.2459
2020-10-07 2020-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 2,172 -46,930 -95.58 959 -94.61 0.0054
2020-07-21 2020-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 49,102 -137,536 -73.69 17,792 -66.39 0.1141
2020-04-17 2020-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 186,638 180,464 2,922.97 52,931 2,538.63 0.4236
2020-01-17 2019-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 6,174 -148,826 -96.02 2,006 -95.56 0.0126
2019-10-16 2019-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 155,000 49,831 47.38 45,147 46.17 0.3022
2019-08-12 2019-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 105,169 27,276 35.02 30,886 44.86 0.2320
2019-04-26 2019-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 77,893 21,229 37.46 21,321 68.13 0.2000
2019-01-23 2018-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 56,664 38,692 215.29 12,681 189.06 0.1437
2018-10-29 2018-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 17,972 -39,476 -68.72 4,387 -63.13 0.0433
2018-07-17 2018-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 57,448 -14,540 -20.20 11,900 -19.94 0.1374
2018-04-30 2018-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 71,988 71,988 14,863 0.1936
2018-01-25 2017-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 0 -40,243 -100.00 0 -100.00
2017-10-18 2017-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 40,243 40,243 7,614 0.0707
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2025-01-14 2024-12-31 13F THERMO FISHER SCIENTIFIC CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2024-10-23 2024-09-30 13F THERMO FISHER SCIENTIFIC CALL Call 1,000 -16.67 619 -6.79 n/a n/a n/a
2024-07-18 2024-06-30 13F THERMO FISHER SCIENTIFIC CALL Call 1,200 0.00 664 -4.88 n/a n/a n/a
2024-04-24 2024-03-31 13F THERMO FISHER SCIENTIFIC CALL Call 1,200 0.00 697 9.59 n/a n/a n/a
2024-01-17 2023-12-31 13F THERMO FISHER SCIENTIFIC CALL Call 1,200 637 n/a n/a n/a
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.